You could all but hear the leftwing jaws thudding to the ground. Shortly after opening an investigation of war crimes in Gaza, the Israeli military police has just snapped it shut.

Those soldiers who described unlawful practices in the Palestinian strip were just relaying "hearsay" and rumours, was the swift conclusion. And just as fast came the stunned reaction from those who wondered if the investigation was, well, just a bit too swift. Amos Harel of Ha'aretz newspaper pointed out that it took just 11 days, including two non-work days. Israeli human rights groups deemed it suspicious and called for an independent investigation. Others pointed out that the review focused only on the veracity of soldier testimonials – without examining copious evidence from other quarters.

Now, some Israelis are questioning the purpose of the inquiry. "It doesn't seem like they were trying to find out the truth, but more that it's an attempt to silence the debate," says Yehuda Shaul of Breaking the Silence, a group of army veterans that collates the experiences of soldiers who serve in the occupied West Bank. The fact that the military police knew about those soldier testimonials but did not activate an inquiry until there was a public furore over them seems to back Shaul's observation.

When Ha'aretz ran transcripts from soldiers coming out of Gaza – shocking accounts of human rights violations against Palestinian civilians during the three-week Israeli assault – it did open up a debate within Israeli society, much more so than any Palestinian account or UN report ever could. The feeling is that Israeli soldiers would have no interest in making up such stories. "It really touched people on the street," says Shaul. "I think people were very disturbed by what came out." But the military police investigation effectively gave those stories a get-out: the soldier accounts weren't malicious, but overblown. It was like rapping the knuckles of children who tell fanciful tales. Except that it was backed with a warning that any soldier talking about their recent experiences in Gaza could face prosecution.

Israelis are deeply irked by the seeming global habit of routinely condemning IDF soldiers while turning a blind eye to the practices of other armies, elsewhere. This is fair enough to some degree: if you're going to take the moral high ground over Israel, it helps that you aren't standing on a mound of dead bodies of your own making (Iraqi, Afghani, take your pick). But being as bad as everybody else cannot be the guiding premise of Israeli policy. And what's routinely disregarded, with such deflection, is the underlying assumptions that validate Israeli misdeeds against Palestinians. One brigade leader, speaking of the ground invasion of Gaza weeks ago, said: "The atmosphere in general, from what I understood from most of my men who I talked to ... I don't know how to describe it ... The lives of Palestinians, let's say, is something very, very less important than the lives of our soldiers."

Yigal Levy, professor of political sociology at the Open University, believes that "the issue is not over incidents, of who saw what, but over an atmosphere of values". But, he adds, Israeli society isn't likely to look at these values, understandably preferring to see army malpractices as deviations, rather than the norm. "As long as the military is the people's army, it is perceived to reflect the image of Israeli society," he says of the conscripted forces. "If someone says the military is ugly, it also means that society is ugly – and nobody can admit this sort of failure."

So what the army says about itself – and by extension about society – is accepted as gospel. If a military investigation concludes that there was no deviation from the "most moral army" script, then there wasn't – as always, the army narrative and the public narrative are one and the same. If you could hear the rumble of global disbelief at the closing of the IDF's Gaza probe, in Israel you could just as clearly hear the shutters readily snapping shut over this dismal frame.